Half spiral casing



FIG. 1 is a perspective view of the half spiral casing;

FIG. 2 is a first side view of the half spiral casing;

FIG. 3 is a second side view of the half spiral casing;

FIG. 4 is a third side view of the half spiral casing;

FIG. 5 is a fourth side view of the half spiral casing;

FIG. 6 is a fifth side view of the half spiral casing; and,

FIG. 7 is a sixth side view of the half spiral casing. 

CLAIM The ornamental design for a half spiral casing, as shown and described. 